WordPress database error: [Unknown column ‘menu_order’ in ‘field list’]

How do I begin to make sense of this:
WordPress database error: [Unknown column ‘menu_order’ in ‘field list’]

Briefly, I’ve just installed WP 1.5 as part of upgrading to WP 2.0.2
Intallation is fine (I can read my old posts with categories etc), but when I try a test post I get a page that begins:

WordPress database error: [Unknown column ‘menu_order’ in ‘field list’]
INSERT INTO wp_posts (ID, post_author, post_date, post_date_gmt, post_content, post_title, post_excerpt, post_status, comment_status, ping_status, post_password, post_name, to_ping, post_modified, post_modified_gmt, post_parent, menu_order) VALUES (‘511’, ‘1’, ‘2006-05-17 19:17:16’, ‘2006-05-17 09:17:16’, ‘test_only by Warren Crosbie’, ‘Test’, ”, ‘publish’, ‘open’, ‘open’, ”, ‘test’, ”, ‘2006-05-17 19:17:16’, ‘2006-05-17 09:17:16’, ‘0’, ‘0’)

Warning: Cannot modify header information – headers already sent by (output started at /Users/myname/Sites/wp/wp-includes/wp-db.php:98) in /Users/myname/Sites/wp/wp-admin/post.php on line 170

WordPress database error: [Unknown column ‘guid’ in ‘field list’]
UPDATE wp_posts SET guid = ‘http://domain/~myname/wp/?p=’ WHERE ID = ‘511’